1. Field of the Invention
The present invention relates to an imaging device, a medium type determining device, and an image forming apparatus.
2. Description of the Related Art
Imaging devices are known that capture, by a two-dimensional image sensor, patterns (patches) printed on a print medium by an image forming apparatus using a coloring material such as ink and convert obtained RGB values of the patterns into color specification values (colorimetric values) in a standard color space, thereby performing the colorimetry of the patterns (refer to Japanese Laid-open Patent Publication No. 2012-63270, for example). The imaging device disclosed in Japanese Laid-open Patent Publication No. 2012-63270 is mounted on a carriage of an image forming apparatus and performs the colorimetry of patterns printed on a print medium by the image forming apparatus.
Meanwhile, the function to determine the type of print media on which images are printed is a function required for image forming apparatuses. For example, Japanese Laid-open Patent Publication No. 2012-194445 discloses an image forming apparatus having an optical sensor that determines the type of a print medium based on the intensity of specular light from the print medium.
For example, a configuration that receives specular light from a print medium using the two-dimensional image sensor included in the imaging device disclosed in Japanese Laid-open Patent Publication No. 2012-63270 can achieve a convenient imaging device that has both the function to perform the colorimetry of patterns and the function to determine the type of print media.
However, the imaging device disclosed in Japanese Laid-open Patent Publication No. 2012-63270 includes a light transmission member that transmits light in a housing, and when specular light from a print medium is received by the two-dimensional sensor, it is expected that specular light from the bottom face of the light transmission member also enters the two-dimensional sensor. If the optical images of these pieces of specular light overlap one another on a light-receiving face of the two-dimensional sensor, a problem arises in that the specular light from the print medium cannot accurately be detected.